Boron nitride/yttria composite components of semiconductor processing equipment and method of manufacturing thereof

ABSTRACT

A corrosion resistant component of semiconductor processing equipment such as a plasma chamber includes a boron nitride/yttria composite containing surface and process for manufacture thereof.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to semiconductor processingequipment and a method of improving corrosion resistance of suchcomponents.

[0003] 2. Description of the Related Art

[0004] In the field of semiconductor processing, vacuum processingchambers are generally used for etching and chemical vapor deposition(CVD) of materials on substrates by supplying an etching or depositiongas to the vacuum chamber and application of an RF field to the gas toenergize the gas into a plasma state. Examples of parallel plate,transformer coupled plasma (TCP™) which is also called inductivelycoupled plasma (ICP), and electron-cyclotron resonance (ECR) reactorsand components thereof are disclosed in commonly owned U.S. Pat. Nos.4,340,462; 4,948,458; 5,200,232 and 5,820,723. Because of the corrosivenature of the plasma environment in such reactors and the requirementfor minimizing particle and/or heavy metal contamination, it is highlydesirable for the components of such equipment to exhibit high corrosionresistance.

[0005] During processing of semiconductor substrates, the substrates aretypically held in place within the vacuum chamber by substrate holderssuch as mechanical clamps and electrostatic clamps (ESC). Examples ofsuch clamping systems and components thereof can be found in commonlyowned U.S. Pat. Nos. 5,262,029 and 5,838,529. Process gas can besupplied to the chamber in various ways such as by gas nozzles, gasrings, gas distribution plates, etc. An example of a temperaturecontrolled gas distribution plate for an inductively coupled plasmareactor and components thereof can be found in commonly owned U.S. Pat.No. 5,863,376. In addition to the plasma chamber equipment, otherequipment used in processing semiconductor substrates include transportmechanisms, gas supply systems, liners, lift mechanisms, load locks,door mechanisms, robotic arms, fasteners, and the like. The componentsof such equipment are subject to a variety of corrosive conditionsassociated with semiconductor processing. Further, in view of the highpurity requirements for processing semiconductor substrates such assilicon wafers and dielectric materials such as the glass substratesused for flat panel displays, components having improved corrosionresistance are highly desirable in such environments.

[0006] Aluminum and aluminum alloys are commonly used for walls,electrodes, substrate supports, fasteners and other components of plasmareactors. In order to prevent corrosion of the such metal components,various techniques have been proposed for coating the aluminum surfacewith various coatings. For instance, U.S. Pat. No. 5,641,375 disclosesthat aluminum chamber walls have been anodized to reduce plasma erosionand wear of the walls. The '375 patent states that eventually theanodized layer is sputtered or etched off and the chamber must bereplaced. U.S. Pat. No. 5,895,586 states that a technique for forming anerosion resistant film of Al₂O₃, AlC, TiN, TiC, AlN or the like onaluminum material can be found in Japanese Application Laid-Open No.62-103379.

[0007] U.S. Pat. No. 5,680,013 states that a technique for flamespraying AtO₃ on metal surfaces of an etching chamber is disclosed inU.S. Pat. No. 4,491,496. The '013 patent states that the differences inthermal expansion coefficients between aluminum and ceramic coatingssuch as aluminum oxide leads to cracking of the coatings due to thermalcycling and eventual failure of the coatings in corrosive environments.In order to protect the chamber walls, U.S. Pat. Nos. 5,366,585;5,798,016; and 5,885,356 propose liner arrangements.

[0008] For instance, the '016 patent discloses a liner of ceramics,aluminum, steel and/or quartz with aluminum being preferred for its easeof machinability and having a coating of aluminum oxide, SC₂O₃ or Y₂O₃,with Al₂O₃ being preferred for coating aluminum to provide protection ofthe aluminum from plasma. The '585 patent discloses a free standingceramic liner having a thickness of at least 0.005 inches and machinedfrom solid alumina. The '585 patent also mentions use of ceramic layerswhich are deposited without consuming the underlying aluminum can beprovided by flame sprayed or plasma sprayed aluminum oxide. The '356patent discloses a ceramic liner of alumina and a ceramic shield ofaluminum nitride for the wafer pedestal. U.S. Pat. No. 5,885,356discloses ceramic liner materials for use in CVD chambers.

[0009] Various coatings have been proposed for metal components ofsemiconductor processing equipment. For instance, U.S. Pat. No.5,879,523 discloses a sputtering chamber wherein a thermally sprayedcoating of AlO₃ is applied to a metal such as stainless steel oraluminum with an optional NiAl_(x) bond coating therebetween. U.S. Pat.Nos. 5,522,932 and 5,891,53 disclose a rhodium coating for metalcomponents of an apparatus used for plasma processing of substrates withan optional nickel coating therebetween. U.S. Pat. No. 5,680,013discloses non-bonded ceramic protection for metal surfaces in a plasmaprocessing chamber, the preferred ceramic material being sintered AlNwith less preferred materials including aluminum oxide, magnesiumfluoride, and magnesium oxide. U.S. Pat. No. 5,904,778 discloses a SiCCVD coating on free standing SiC for use as a chamber wall, chamberroof, or collar around the wafer.

[0010] With regard to plasma reactor components such as showerhead gasdistribution systems, various proposals have been made with respect tothe materials of the showerheads. For instance, commonly owned U.S. Pat.No. 5,569,356 discloses a showerhead of silicon, graphite, or siliconcarbide.

[0011] U.S. Pat. No. 5,494,713 discloses forming an alumite film on analuminum electrode and a silicon coating film such as silicon oxide orsilicon nitride over the alumite film. The '713 patent states that thethickness of the silicon coating film should be 10 μm or less,preferably about 5 μm, since the aluminum coating film, the alumitecoating film and the silicon coating film have different coefficients oflinear expansion and cracks are easily generated when the thickness ofthe silicon coating film is too thick. A thickness below 5 μm, however,is stated to be unfavorable since the protection of the aluminumsubstrate is insufficient. U.S. Pat. No. 4,534,516 discloses an uppershowerhead electrode of stainless steel, aluminum, copper or the like.U.S. Pat. No. 4,612,077 discloses a showerhead electrode of magnesium.U.S. Pat. No. 5,888,907 discloses a showerhead electrode of amorphouscarbon, SiC or Al. U.S. Pat. Nos. 5,006,220 and 5,022,979 disclose ashowerhead electrode either made entirely of SiC or a base of carboncoated with SiC deposited by CVD to provide a surface layer of highlypure SiC.

[0012] In view of the need for high purity and corrosion resistance forcomponents of semiconductor processing equipment, there is a need in theart for improvements in materials and/or coatings used for suchcomponents. Moreover, with regard to the chamber materials, anymaterials which can increase the service life of a plasma reactorchamber and thus reduce the down time of the apparatus, would bebeneficial in reducing the cost of processing the semiconductor wafers.

SUMMARY OF THE INVENTION

[0013] According to a first aspect of the invention a process forproviding an erosion resistant boron nitride/yttria composite containingcoating on a surface of a semiconductor processing equipment componentis provided. The process includes depositing a boron nitride/yttriacomposite containing coating on a surface of a processing equipmentcomponent so as to form an outer erosion resistant surface. By erosionresistant surface, it is meant a surface coating that protectsunderlying materials from the corrosive effects of plasma chamber gases,while resisting erosion of the coating by the plasma chamber gases. Theunderlying surface of the process equipment component to be coated cancomprise a metal, ceramic or polymer material with a preferable materialbeing anodized aluminum.

[0014] In a preferred embodiment, one or more intermediate metal,ceramic or polymer coatings may be used between the surface of thesemiconductor processing equipment and the boron nitride/yttriacomposite containing coating. Metal surfaces that may be coated includeanodized or unanodized aluminum, stainless steel, a refractory metalsuch as molybdenum or other metal or alloy used in plasma chambers.Ceramic surfaces that may be coated include alumina, SiC, AIN, Si₃N₄, BCor other plasma compatible ceramic material. Polymeric surfaces that maybe coated include fluoropolymers such as Teflon®, polyimides such asVespel®, and other polymeric materials useful in a plasma chamber attemperatures up to 200° C.

[0015] According to a second aspect of the invention, a metal componentis provided. The component includes: (a) a metal surface; (b) anoptional first intermediate coating on the metal surface; (c) anoptional second intermediate coating on the first intermediate coatingor on the metal surface; and a boron nitride/yttria composite containingcoating on said component which provides a corrosion resistant outersurface. Each of the first and second intermediate coatings may be ametal or alloy thereof, ceramic, polymer or mixture or composite ofmaterials used in plasma chamber reactors.

[0016] According to another aspect of the invention, there is provided asemiconductor processing equipment component made of a boronnitride/yttria composite containing material. The component may includeany one or more coatings employed in such equipment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The objects and advantages of the invention will become apparentfrom the following detailed description of the preferred embodimentsthereof in connection with the accompanying drawing, in which:

[0018]FIG. 1 is a schematic cross-sectional view of a plasma reactorchamber having a component coated with a corrosion resistant coating inaccordance with the present invention.

[0019]FIG. 2 shows details of the corrosion resistant coating in detailA of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

[0020] The invention provides an effective way to provide corrosionresistance to metal, ceramic and polymer surfaces of components ofsemiconductor processing apparatus such as parts of a plasma processingreactor chamber by utilizing an erosion resistant coating. Suchcomponents include chamber walls, substrate supports, gas distributionsystems including showerheads, baffles, rings, nozzles, etc., fasteners,heating elements, plasma screens, liners, transport module components,such as robotic arms, fasteners, inner and outer chamber walls, etc.,and the like.

[0021] Although the invention is applicable to any type of componenthaving a metal, ceramic or polymer surface, for ease of illustration,the invention will be described in more detail with reference to theapparatus described in U.S. Pat. No. 5,820,723 which is incorporatedherein by reference in its entirety.

[0022]FIG. 1 illustrates a vacuum processing reactor chamber 10 thatincludes a substrate holder 70 providing an electrostatic clamping forceto a substrate 60 as well as providing an RF bias to the substrate whileit is He backcooled. A focus ring 72 confines plasma in an area abovethe substrate. A source of energy for maintaining a high density (e.g.,10¹¹-10¹² ions/cm³) plasma in the chamber such as an antenna 40 poweredby a suitable RF source to provide a high density plasma is disposed atthe top of reactor chamber 10. The chamber includes suitable vacuumpumping apparatus for maintaining the interior 30 of the chamber at adesired pressure (e.g., below 50 mTorr, typically 1-20 mTorr) byevacuating the chamber through the centrally located vacuum port 20 atthe bottom of the chamber.

[0023] A substantially planar dielectric window 50 of uniform thicknessprovided between the antenna 40 and the interior of the processingchamber 10 forms the vacuum wall at the top of the processing chamber10. A gas distribution plate 52 is provided beneath window 20 andincludes openings such as circular holes for delivering process gas froma gas supply to the chamber 10. A conical liner 54 extends from the gasdistribution plate and surrounds the substrate holder 70.

[0024] In operation, a semiconductor substrate such as a silicon wafer60 is positioned on the substrate holder 70 and is typically held inplace by an electrostatic clamp 74 while He backcooling is employed.Process gas is then supplied to the vacuum processing chamber 10 bypassing the process gas through a gap between the window 50 and the gasdistribution plate 52. Suitable gas distribution plate arrangements(i.e., showerhead) are disclosed in commonly owned U.S. Pat. Nos.5,824,605; 6,048,798; and 5,863,376, the disclosures of which are herebyincorporated by reference. For instance, while the window and gasdistribution plate arrangement in FIG. 1 are planar and of uniformthickness, non-planar and/or non-uniform thickness geometries can beused for the window and/or gas distribution plate. A high density plasmais ignited in the space between the substrate and the window bysupplying suitable RF power to the antenna 40.

[0025] Chamber walls 28 such as anodized or unanodized aluminum wallsand metal, ceramic or polymer components such as the substrate holder70, fasteners 56, liners 54, etc., that are exposed to plasma and showsigns of corrosion are candidates for coating according to theinvention, thus avoiding the need to mask them during operation of theplasma chamber. Examples of metals and/or alloys that may be coatedinclude anodized or unanodized aluminum and alloys thereof, stainlesssteel, refractory metals such as W and Mo and alloys thereof, copper andalloys thereof, etc. Examples of ceramic surfaces that may be coatedinclude alumina, SiC, AlN, Si₃N₄, BC and TiO₂. Examples of commerciallyavailable polymer materials that may be coated include fluoropolymerssuch as Teflon®, polyimides such as Vespel®, and other polymericmaterials useful in a plasma chamber at temperatures up to 200° C. In apreferred embodiment, the component to be coated is a chamber wall 28having an anodized or unanodized aluminum surface 29. The coatingaccording to the invention permits use of aluminum alloys without regardas to its composition (thus allowing use of more economical aluminumalloys in addition to highly pure aluminum), grain structure or surfaceconditions. In the following discussion, an example of a component to becoated is an aluminum chamber wall 28 having a first optionalintermediate coating 80, a second optional intermediate coating 90 and aboron nitride/yttria composite containing coating 100, as illustrated inFIG. 2.

[0026] In order to ensure good adhesion of the coated material, thesurface of the aluminum substrate 28 is preferably thoroughly cleaned toremove surface material such as oxides or grease prior to coating. Inaddition, it is particularly desirable to roughen the substrate surface,anodize the substrate surface and again roughen the anodized substratesurface prior to application of any of the desired coatings.

[0027] According to the invention, a first intermediate coating 80 isoptionally coated on the aluminum sidewall 28 by a conventionaltechnique. The optional first intermediate coating 80 is sufficientlythick to adhere to the substrate and to further allow it to be processedprior to forming the optional second intermediate coating 90 or thediamond containing coating described below. The first intermediatecoating 80 can have any suitable thickness such as a thickness of atleast about 0.001 inches, preferably from about 0.001 to about 0.25inches, more preferably between 0.001 and 0.1 inches and most preferablyfrom 0.001 inches to 0.05 inches.

[0028] After depositing the optional first intermediate coating 80 ontoaluminum substrate 28, the plating can be blasted or roughened by anysuitable technique, and then overcoated with the second optional coating90 or the boron nitride/yttria composite containing coating 100. Aroughened layer 80 provides a particularly good bond. Desirably, thesecond intermediate coating 90 imparts a high mechanical compressionstrength to the coating 80 and minimizes formation of fissures in thecoating 90.

[0029] The optional second intermediate coating 90 is sufficiently thickto adhere to the first intermediate coating 80 and to further allow itto be processed prior to forming any additional intermediate coatings orthe outer boron nitride/yttria composite containing coating 100described below. The second intermediate coating 90 can have anysuitable thickness such as a thickness of at least about 0.001 inches,preferably from about 0.001 to about 0.25 inches, more preferablybetween 0.001 and 0.1 inches and most preferably between 0.001 inchesand 0.05 inches.

[0030] The first and second intermediate coating may be made of any oneor more materials employed in conventional plasma processing chambers.Examples of such materials include metals, ceramics and polymers.Particularly desirable metals include any one or more refractory metals,composites or alloys containing such metals. Particularly desirableceramics include Al₂O₃, SiC, Si₃N₄, BC, AlN, TiO₂, etc. Particularlydesirable polymers include fluoropolymers such as Teflon®, polyimidessuch as Vespel®, and other polymeric materials useful in a plasmachamber at temperatures up to 200° C. Specific materials contemplatedfor the intermediate layers also include fullerene containing materials;other hard carbon containing materials such as diamond and diamond-likematerials; carbides, borides, nitrides and/or carbonitrides of, forexample, hafnium, tantalum, titanium and/or silicon; boron carbides;boron nitrides; boron carbonitrides; zirconia; yttria or mixtures of anyof the above-mentioned materials.

[0031] It is contemplated that the first and second intermediate layers80 and 90, which are optional may be any one of the above-mentionedmaterials such that the coatings are the same or different depending onthe desired properties. It is also anticipated that additionalintermediate coatings such as a third, fourth or fifth intermediatecoating of the same or different materials may be employed.

[0032] The boron nitride/yttria composite containing coating 100 isdeposited on the optional second intermediate coating 90, or on theoptional first intermediate coating 80, or on the aluminum substrate 28.The thickness of the boron nitride/yttria composite containing coatingis desirably at least 0.001 inches; preferably from about 0.001 to about0.25 inches, more preferably from about 0.001 to about 0.1 inches andmost preferably from 0.001 to 0.05 inches. The thickness of the boronnitride/yttria composite containing coating 100 can be selected to becompatible with the plasma environment to be encountered in the reactor(e.g., etching, CVD, etc.). This layer of boron nitride/yttria compositecontaining coating may be coated on all or part of the reactor chamberand components as discussed above. Most desirably, the boronnitride/yttria composite coatings are of a thickness useful to provideerosion and/or corrosion protection to the underlying layers, andparticularly the substrate, for a significant period of exposure to thecorrosive chamber gases.

[0033] The boron nitride/yttria composite containing coating 100 of thepresent invention contains both boron nitride and yttria. The boronnitride component of the composite may be any one of hexagonal, cubic ormixture thereof. Most desirably the boron nitride component is 100%cubic phase or contains proportions of cubic phase exceeding 60% byweight, preferably exceeding 80% by weight and most preferably exceeding90% by weight. The cubic form of boron nitride has a much higherdensity, is very hard and may be produced from the hexagonal form athigh temperature and pressure. Alternatively, the boron nitride may be100% hexagonal phase.

[0034] The yttria component of the composite may be present in an amountbetween about one percent and 99 percent, more desirably between about40 and 99 percent and even more desirably between about 60 and 80percent of the total composite. The boron nitride component may bepresent in an amount between about one percent and 99 percent, moredesirably between about one and 60 percent and even more desirablybetween about 20 and 40 percent of the total composite.

[0035] The composite may include other protective materials in amountsup to about fifty percent of the total composite or greater. Desirably,boron nitride, yttria or zirconia form a continuous matrix phase in suchcomposites. More desirably, the composites of the present inventioninclude between about one and 40 percent by weight additional material,and more preferably between about one and 20 percent by weightadditional material and even more preferably between about one and 10percent by weight additional material based upon the composite.

[0036] Such materials may include any one or more materials employed inplasma processing chambers. Examples of such materials include any oneor more metals, ceramics or polymers. Particularly desirable metalsinclude any one or more refractory metals, composites or alloyscontaining such metals. Particularly desirable ceramics include Al₂O₃,SiC, Si₃N₄, BC, AlN, TiO₂, etc. Particularly desirable polymers includefluoropolymers such as Teflon®, polyimides such as Vespel® and otherpolymeric materials useful in a plasma chamber at temperatures up to200° C. It is believed that the most desirable materials would include aboron nitride/yttria composite alone or in combination with carbides,borides, nitrides and/or carbonitrides of, for example, hafnium,tantalum, titanium and/or silicon; boron carbides; boron nitrides; boroncarbonitrides; zirconia; yttria or mixtures of the above-mentionedmaterials.

[0037] The boron nitride/yttria composite containing coating 100 of thepresent invention may be deposited onto the desired surface by any knowncoating technique such as thermal spraying, plasma spraying, chemicalvapor deposition, sublimation, laser vaporization, sputtering, sputterdeposition, ion beam coating, spray coating, dip coating, evaporation,roll-on coating brush coating, etc. It is also contemplated thatmultiple boron nitride/yttria composite containing coatings with orwithout intermediate layers of other materials may be deposited onto thedesired surface using any suitable technique.

[0038] In an alternative aspect of the invention, there is provided asemiconductor processing equipment component made of a boronnitride/yttria composite containing material. The component may includeany one or more coatings conventionally employed in such equipment.

[0039] By use of the boron nitride/yttria composite containing coatingsor components of the present invention, it is preferred to obtain anultrahard, erosion resistant surface. Such coating or component isdesirably free of materials that react with processing chamber gases andare chemically inert such that there is low or no particlecontamination, little or no corrosion, little or no metal contaminationand/or little or no volatile etch products.

[0040] It is preferred that boron nitride/yttria composite containingcoating or component be placed in the regions that may or may not beexposed to the plasma environment such as parts in direct contact withthe plasma or parts behind chamber components such as liners, etc., toprevent metal contamination of the semiconductor substrates processed inthe reactor chamber. It is particularly preferred to limit or excludetransition metal dust; e.g., any one or more of elements 21 through 29(scandium through copper), 39 through 47 (yttbrium through silver), 57through 79 (lanthanum through gold) and all known elements from 89(actinium) on in the Periodic Table. Thereby, according to one advantageof the present invention, unsatisfactory etching or undesirableformation of pinholes in deposited films is reduced by suppressingoccurrence of such dust by either erosion or corrosion.

[0041] While the invention has been described in detail with referenceto specific embodiments thereof, it will be apparent to those skilled inthe art that various changes and modifications can be made, andequivalents employed, without departing from the scope of the appendedclaims.

What is claimed is:
 1. A process of coating a surface of a component ofsemiconductor processing equipment, the processing comprising: (a)optionally depositing a first intermediate coating on a surface of acomponent of semiconductor processing equipment; (b) optionallydepositing a second intermediate coating on said first intermediatelayer or on said surface; and (c) depositing a boron nitride/yttriacomposite containing coating on said component to form an outer erosionresistant surface.
 2. The coating process according to claim 1, whereinsaid surface of said component comprises a metal, ceramic or polymersurface.
 3. The coating process according to claim 2, wherein saidsurface is anodized aluminum.
 4. The coating process according to claim1, wherein said first intermediate coating is not optional.
 5. Thecoating process according to claim 4, wherein said first intermediatecoating comprises a metal, ceramic or polymer coating.
 6. The coatingprocess according to claim 1, wherein said component comprises a chamberwall of a plasma etching chamber.
 7. The coating process according toclaim 1, further comprising forming a roughened surface on saidcomponent, said diamond containing coating being deposited on saidroughened surface.
 8. The coating process according to claim 1, whereinsaid boron nitride/yttria composite containing coating includes a cubicphase, a hexagonal phase or mixtures thereof.
 9. The coating processaccording to claim 1, wherein said boron nitride/yttria compositecontaining coating comprises at least one material other than boronnitride or yttria.
 10. The coating process according to claim 9, whereinsaid other material is a metal, ceramic or polymer.
 11. The coatingprocess according to claim 10, wherein said other material is zirconia.12. The coating process according to claim 10, wherein said othermaterial comprises titanium carbide, titanium boride, titanium nitride,silicon carbide, silicon boride, silicon nitride or mixtures thereof.13. The coating process according to claim 9, wherein said yttriacomprises from about 60 to about 80 percent by weight of said composite.14. The coating process according to claim 13, wherein said boronnitride comprises from about 20 to about 40 percent by weight of saidcomposite.
 15. The coating process according to claim 1, wherein saidboron nitride/yttria composite containing coating is deposited bychemical vapor deposition, plasma spray coating, sublimation, laservaporization, sputtering, sputtering deposition, ion beam coating, spraycoating, dip coating, evaporation coating, roll-on coating or brushcoating.
 16. A component of semiconductor processing equipmentcomprising: (a) a surface; (b) an optional first intermediate coating onsaid surface; (c) an optional second intermediate coating on said firstintermediate coating or on said surface; and (d) a boron nitride/yttriacomposite containing coating on said component that forms an outercorrosion resistant surface.
 17. The component according to claim 16,wherein the surface is a metal, ceramic or polymer surface.
 18. Thecomponent according to claim 17, wherein said surface is anodizedaluminum.
 19. The component according to claim 16, wherein said firstintermediate coating is not optional.
 20. The component according toclaim 16, wherein said component comprises a chamber wall of a plasmaetching chamber.
 21. The component according to claim 12, wherein saidboron nitride/yttria composite includes a cubic phase, a hexagonal phaseor mixtures thereof.
 22. The component according to claim 16, whereinsaid boron nitride/yttria composite containing coating comprises atleast one material other than boron nitride and yttria.
 23. Thecomponent according to claim 22, wherein said other material is a metal,ceramic or polymer.
 24. The component according to claim 23, whereinsaid other material is zirconia.
 25. The component according to claim23, wherein said other material comprises titanium carbide, titaniumboride, titanium nitride, silicon carbide, silicon boride, siliconnitride or mixtures thereof.
 26. The component according to claim 16,wherein said yttria comprises from about 60 to about 80 percent byweight of said composite.
 27. The component according to claim 16,wherein said boron nitride comprises from about 20 to about 40 percentby weight of said composite.
 28. The component according to claim 16,further comprising one or more additional boron nitride/yttria compositecontaining or intermediate coatings.
 29. The component according toclaim 16, wherein boron nitride or yttria form a continuous matrix phasein said boron nitride/yttria containing coating.
 30. A component ofsemiconductor processing equipment having at least one surface exposedto plasma in the equipment, the component comprising a boronnitride/yttria composite containing material forming a surface at least0.001 inches thick exposed to plasma in the equipment.
 31. The componentaccording to claim 29, wherein said entire component is made of saidboron nitride/yttria composite containing material.